Effect of vowel identity and onset asynchrony on concurrent vowel identification.
OBJECTIVE
The purpose of the current study was to determine the effects of vowel identity and temporal onset asynchrony on identification of vowels overlapped in time.


METHODS
Fourteen listeners with normal hearing, with a mean age of 24 years, participated. The listeners were asked to identify both of a pair of 200-ms vowels (referred to as double vowels) presented either simultaneously or with a temporal asynchrony ranging from 25 ms to 150 ms in 25-ms steps. The stimuli were synthetic steady-state vowels /i ae u / arranged in seven combinations: /u i/, /ae /, / /, / ae/, /ae i/, / i/, and / u/.


RESULTS
Listeners' responses revealed that one vowel of a pair was identified correctly more often than the other vowel (known as vowel dominance). Vowel dominance effects were seen for 6 of the 7 vowel pairs, and there was improvement of vowel identification with increasing temporal separation between vowels for 5 of the 7 pairs. Vowel pairs with the vowel // consistently yielded improved identification with increases in temporal asynchrony.


CONCLUSIONS
Peripheral masking cannot explain the patterns of results of this study. A more parsimonious explanation may be perceptual anchoring.
Hedrick
Mark S
MS
University of Tennessee, Knoxville, Department of Audiology and Speech Pathology, 578 South Stadium Hall, Knoxville, TN 37996-0740, USA. mhedric1@utk.edu
Madix
Steven G
SG
D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D010470:Perceptual Masking; D010700:Phonetics; D013060:Speech; D013061:Speech Acoustics; D013067:Speech Perception; D013647:Task Performance and Analysis; D013997:Time Factors; D055815:Young Adult